Apparatus for injecting fluids into production zones of multiple completion wells



y 1964 R L. MCGLASSON ETAL 3, 2,694

APPARATUS FOR fNJECTING FLUIDS INTO PRODUCTION ZONES OF MULTIPLE COMPLETION WELLS Flled Oct. 20, 1960 2 Sheets-Sheet 1 IIIIIIIIIIIIIIIIIIA INVENTORS ROBERT L. M: GLA sso/v WALTON 0. GREA THOUSE F G, JAMES E. LANDERS CHA RLES M. HUDG/NS, JR.

A TTORNE Y y 1964 R L. MCGLASSON ETAL 3,132,694

APPARATUS FOR INJECTING FLUIDS INTO PRODUCTION ZONES 0F MULTIPLE COMPLETION WELLS Filed Oct. 20, 1960 2 Sheets-Sheet 2 INVENTORS ROBERT L. MCGLASSON WALTON D. GREA THOUSE JAMES E LANDERS CHARLES M. HUDG/NS, JR.

ATTORNEY United States Patent AIRARATUS FOR INJECTING FLUmS INTO PRO- DUCTION ZONES 0F MULTIPLE COMPLETION WELLS Robert L. McGlasson, Ponca City, Okla, Walton D. Greathouse, Houston, Tex., and James E. Landers and Charles M. Hudgins, Jr., Ponca City, Okla, assignors to Continental Oil Company, Ponca City, Okla, a corporation of Delaware Filed Oct. 20, 1960, Ser. No. 63,801 5 Claims. (Cl. 166-139) This invention relates to apparatus for chemically treating oil and gas wells. More particularly, but not by way of limitation, the present invention relates to an apparatus for injecting fluids into the several producing zones of multiple completion oil and gas wells.

Chemical treatment of the casing and tubing of a producing oil or gas well at frequent intervals throughout the life of the well is essential to the assurance of eflicient and trouble-free production. For example, the injection of an appropriate fluid containing a corrosion inhibiting chemical agent into the producing zone of the well bore considerably extends the life of the casing and producing tubing string or strings.

In low pressure, single completion wells (that is, wells having only a single producing zone), the problem of introducing an appropriate treating fluid into the producing zone is relatively simple. 'If the annulus between the producing tubing string and the casing is open for the entire depth of the well, it is only necessary to introduce the chemical into the annulus at the top of the well and permit it to gravitate downwardly. In the case of multiple completion wells, on the other hand, the several producing zones are defined by packers which, of course, render the annulus unavailable as a conduit for conveying the fluid to the lower producing zones. Chemical treatment of multiple completion wells is currently accomplished =by shutting in the well and pumping the treating fluid down the producing tubing string, or by installing small diameter'tubing strings inside each producing tubing string. In either method, oil production is temporarily lost, or is reduced severly, and the cost of labor and materials is high.

The present invention contemplates an apparatus for injecting treating fluid into the several producing zones of a multiple completion Well. prises a small, heavy-Walled string of tubing which may be installed simultaneously with the installation of the producing tubing string or strings. The fluid injection string extends through the packers defining the multiple producing zones and the string is fitted with preset differential pressure, injection-bypass valves located just below each production packer in each producing zone. Suitable fluid supply and pressure control equipment is located on the surface near the wellhead and is connected to the fluid injection string. p

The ditlerential pressure, injection-bypass valves are individually preset so that at a given pressure of fluid, the valve in the uppermost producing zone will open to permit the treating fluid to be injected into the annulus between the casing and the producing tubing string. With a further increase in the pressure applied to the treating fluid in the fluid injection string, the uppermost valve will close, but will permit the fluid to pass through the valve and continue down the string to thenext lower valve located in the next producing zone. This second valve is preset to open at a pressure slightly higher than the bypass pressure of the uppermost valve. Successive valves in lower producing zones are, in the same manner, set to open at a pressure slightly higher than the pressure required to close the valve next thereabove. Thus, suc- The apparatus com cessive zones may be selectively treated by proper control of the pressure applied to the fluid at the surface. It is also possible to simultaneously treat several or all of the producing zones by proper adjustment of the actuation pressures of the valves.

It is a broad object of the present invention to provide an apparatus for selectively treating the several producing zones of multiple completion wells.

It is a further object of the present invention to provide an apparatus for injecting treating fluid into an oil or gas well having a plurality of producing zones, which apparatus may be installed in the well simultaneously with the running of the producing tubing string.

Another object of this invention is to provide a treating fluid apparatus for use in multiple completion wells, which apparatus may be easily controlled entirely from the surface to permit treating fluid to be injected into any or all of the producing zones as desired.

An additional object of the invention is the provision of apparatus which permits chemical treatment of multiple completion wells with a minimum of equipment and lost time.

Another object of the invention is to provide an apparatus for fluid treating multiple completion oil and gas wells which is of simple construction and which is characterized by a long and eflicient operating life.

These objects wll be better understood, and other objects and advantages will become apparent, when the following description of the apparatus is considered conjunctively with the accompanying drawings in which:

FIGURE 1 is a schematic illustration of the apparatus of the present invention as it appears when installed in a multiple completion well.

FIGURE 2 is a cross-sectional view through a portion of the well showing the way in which the fluid injection tubing and one of the bypass valves are installed in a preiferred embodiment of the invention. The bypass valve is schematically illustrated in cross section.

Referring now to the drawings, and particularly to FIG. 1, reference character 10 designates the casing of a multiple completion Well. Such wells are characterized by a plurality of producing zones. Three of these zones are illustrated in FIG. 1 and are designated by reference characters 12, 14 and 16. The producing zones 12, 14 and 16 are segregated from each other and from the bore of the well above the uppermost producing zone '12 by a series of packers 18, 20 and 22. Producing tubing strings 24, 26 and 28 extend downwardly in the well bore and terminate in the producing zones 12, 1-4 and .16, respectively.

In accordance with the present invention, a string of fluid injection tubing 30 which is characterized by a thick wall and a relatively small diameter, say, of the order of 1 inch, originates at the wellhead and extends downwardly in the well through the packers 18, 20 and 22. The injection tubing 30 is fitted with a plurality of preset, pressure differential, injection-bypass valves 32, 34 and 36 which are located in the producing zones 12, 14 and 16, respectively. At the Wellhead, the injection tubing 30 is fitted with a pressure gauge 38 and is connected via conduit 40 through a pressure control valve 42 and a suitable fluid pump 44 to a source of supply 46 of the fluid packer 18 is characterized by a vertical bore 54 of small diameter which extends thercthrough between the injection tubing 30 and the bypass valve 32.

The valve body 43 has an enlarged bore 56 in the lower portion 52 thereof and a bore 58 of smaller diameter in the remaining portion of the valve body. A piston 60 is slidingly fitted in the smaller bore 58 in the upper portion 50 of the valve body, and is characterized by a fluid conduit 62 which originates at the upper surface of the piston 60 and terminates in the side thereof. The piston 60 is circumferentially grooved for the accommodation of an O-ring seal 63 which moves with the piston 60 as it slides in the smaller bore 58 and provides a sealing fit of the piston in the bore. In some constructions, however, it may be desirable to dispense with the O-ring seal 63 and rely instead upon the metal to metal seal provided by the sliding engagement of the walls of the piston 60 with the smaller bore 58. The piston 66 is supported, and is urged upwardly in the valve bore 58, by a compression spring 64 which is seated upon the end of the portion of the injection tubing 30 which is threadedly connected to the bypass valve 32. The body 48 of the bypass valve 32 is further characterized in having a radial fluid outlet es extending therethrough between the enlarged bore 56 and the position in the valve occupied by the piston 60 when the spring 64- is fully extended.

The construction of each of the preset, injection-bypass valves 34 and 36 which are utilized in conjunction with the injection tubing 30 is identical to the construction of the bypass valve 32 illustrated in FIG. 2. The resiliencies of the compression springs 64 employed in the several bypass valves are, however, different in the case of each of the valves and are each preadjusted so that the pressure required to depress the piston of each of the valves is greater in the case of those valves which are located lower in the well. The presetting of the several valves to open sequentially or simultaneously will be further explained in conjunction with the description of the operation of the invention.

Operation The fluid supply source 46 is filled with an appropriate treating fluid and the pump 44 is actuated. As indicated above, the resiliencies of the springs 64 in differential pressure, injection-bypass valves 32 and 3d are preadjusted so that the piston 60 in the uppermost bypass valve 32 will move downwardly into the enlarged bore 56 at a slightly lower pressure than that which is required to force the piston 65 in the next lower bypass valve 34 downwardly a sufficient amount to place the fluid conduit 62 therein in communication with the radial fluid outlet 66. The same adjustments are made in the relative resmaller bore 58 of the valve and effectively blocks the radial fiuid outlet 66 so that no fluid is permitted to enter the producing zone 12, while allowing fluid to flow through the conduit 62 and enlarged bore 56 to the next lower valve. At a higher pressure, the piston 60 moves farther down into the enlarged bore 56 and assumes a second position which permits part of the treating fluid to be injected into the producing zone 12 while the remainder of the fluid passes through the piston 60, through the enlarged bore 56, and on down the injection tubing 30 into the bypass valve 34. It may be desirable under some circumstances of operation to adjust the resiliency of the spring 64 so that the second position will not be assumed under normal operating pressures, thus assuring that no fluid will be injected into the producing zone 12, when the piston 69 is in the bypass position.

After the piston 60 has assumed one of the two bypass positions described above, a further increase in the fluid pressure forces the piston 60 in the next lower valve 34 downwardly in the valve body 48 thereof until the fluid is permitted to enter the producing zone 14 by way of the radial fluid conduit 66. Depending upon which of the two bypass positions the piston 60 in the uppermost valve 32 has assumed (which in turn depends upon the preadjusted resilience of the spring 64), the producing zones 12 and 1d may thus be treated either sequentially or simultaneously. The same is necessarily true of all three of the zones 12, .14 and 16 since it is merely necessary to properly preadjust the resilienoies of the springs 64 in the several valves in order to assure that sequential injection will occur at different pressures, or that simultaneous injection into two or more of the zones will be effected, or that either sequential or simultaneous injection may be effected as between any two adjacent valves.

From the foregoing, it will be apparent that the present invention provides an apparatus for easily and selectively treating the several producing zones of a multiple completion well. The injection tubing string may be conveniently installed in several ways, either concurrently tall/f lth the running of the producing tubing string or thereter.

Changes may be made inthe combination and arrangement of parts or elements as heretofore set forth in the specification and shown in the drawings, it being understood that changes may be made in the embodiments disclosed without departing from the spirit and scope of the V invention as defined in the following claims.

siliencies of the springs 64 in each adjoining pair of bypass valves in the injection tubing 30. The sequence of actuation of the valves 32, 34 and as as the pressure in the injection tubing 30 is increased is therefore as follows:

First, the piston in the uppermost bypass valve 32 is depressed by the pressurized treating fluid until the fluid conduit 62 is placed in communication with the radial fluid outlet 66. At this pressure, the treating fluid will, of course, be injected into the first producing zone 12. Constant control of the pressure in the injection tubing 31) is maintained at the wellhead by manipulation of the pressure control valve 42 and pressure gauge 38. In order to supply treating fluid to the next lower producing zone 14, the pressure in the injection tubing 39 above the uppermost valve 32 is increased sufficiently to force the piston 60 therein downwardly into the enlarged bore 56 in the lower portion 52 of the valve body 48. The treating fluid can then pass through the bypass valve 32 and on down the injection tubing 30 into the bypass valve 34.

It will be apparent, in referring to FIG. 2, that the piston 60 may occupy two alternative bypass positions in the valve body 48 of bypass valve 32. In one of these positions, the body of the piston remains partially in the We claim:

1. Apparatus for injecting a fluid into the producing zones of a multiple completion well comprising:

(a) tubular means in the bore of the well extending dogvnwardly into each of the several pro duoing zones; an

(b) a plurality of bypass valves supported by said tubular means with one of said bypass valves positioned in each of a plurality of said producing zones, said bypass valves each comprising a body portion having a bore therein in communication with said tubular means and having a fluid outlet therein in communication with said bore and with the exterior of said body, said bore having a fluid bypass channel associated with the lower portion thereof;

a piston movable within said bore, said piston including conduit means communicating with the upper portion of said bore and passing through a surface of said piston immediately adjacent a wall of said bore,

said piston being movable relative to said body portion for alternately blocking the flow of fluid through said tubular means, placing the interior of said tubular means above the respective bypass valve in communication through said conduit means, and fluid out-let with the producing zone in which the respective valve is located, and opening (the interior of said tubular means to permit fluid to flow through said conduit means and bypass channel to the next lower producing zone; and

resilient biasing means associated with said bypass valve for urging said piston relative to said tubular means into a position whereby flow of fluid through said tubular means is blocked.

2. Apparatus as claimed in claim 1 wherein said biasing mans in each one of said bypass valves below the uppermost bypass valve is less compressible than the biasing means in the next adjacent bypass valve above said one bypass valve.

3. Apparatus as claimed in claim 1 further characterized in that the bypass channel comprises an enlargement in the lower portion of said bore adjacent one of its ends and in that said resilient means is positioned in the bottom of said tubular body for supporting and urging said piston in an upward direction.

4. In a multiple completion well having a plurality of producing zones, apparatus for injecting a fluid into the several producing zones comprising:

(a) a plurality of packers defining the upper and lower limits of each producing zone, said packers each having an aperture therethrough;

(b) a preset, difterential pressure operated, bypass valve threaded at its upper end into said aperture on the lower side of each packer defining the upper limit of each of said producing zones, each of said bypass valves comprising a body member having a bore therethrough communicating with said aperture and further having a pas sageway communicating with said bore and passing through one portion of said body member, a portion of said bore being reduced in cross-section,

a piston slidably mounted in the reduced cross-sectional portion of said bore and having a channel through the body of said piston positioned to place said passageway in communication the exterior or said body when said piston is moved downwardly to an intermediate position by fluid pressure the upper portion of said bore, and to place the reduced cross-sectional portion of said bore in communication with the remainder oi said bore when said piston is moved to a lower position by increased fluid pressure Within the upper portion of said bore; and

means for urging the piston away irom the portion of said bore of larger cross-section and further into the portion of said bore of reduced cross-section whereby said channel is out of communication with said larger cross-sectional portion of said bore, said individual urging means being progressively less compressible from the upper to the lower one of said individual bypass valves;

(0) tubular members each connected at one of their ends to the lower end of each of said bypass valves in communication with the bore through the body member of the respective bypass valve, and each threaded at their other ends into the aperture through the adjacent packer therebelow;

(d) a source of fluid to be injected into the several zones;

(e) a pump connected to said source; and

(f) a fluid conduit connected at one of its ends to said pump and having its other end threaded into the aperture of the uppermost packer in said well, whereby said source of fluid is placed in communication with said valves.

5. Apparatus as claimed in claim 3 wherein said resilient means is a compression spring and said fluid outlet opens into the bore of said tubular valve body between said enlarged bore and said piston when said spring is fully extended.

References Cited in the file of this patent UNITED STATES PATENTS 1,927,958 Simmons Sept. 26, 1933 2,227,545 Haslam Jan. 7, 1941 2,601,849 Lee July 1, 1952 2,725,014 tPryor Nov. 29, 1955 2,951,536 Garrett Sept. 6, 1960 2,973,039 Payne Feb. 28, 1961 3,007,523 Vincent Nov. 7, 196 1 

1. APPARATUS FOR INJECTING A FLUID INTO THE PRODUCING ZONES OF A MULTIPLE COMPLETION WELL COMPRISING: (A) TUBULAR MEANS IN THE BORE OF THE WELL EXTENDING DOWNWARDLY INTO EACH OF THE SEVERAL PRODUCING ZONES; AND (B) A PLURALITY OF BYPASS VALVES SUPPORTED BY SAID TUBULAR MEANS WITH ONE OF SAID BYPASS VALVES POSITIONED IN EACH OF A PLURALITY OF SAID PRODUCING ZONES, SAID BYPASS VALVES EACH COMPRISING A BODY PORTION HAVING A BORE THEREIN IN COMMUNICATION WITH SAID TUBULAR MEANS AND HAVING A FLUID OUTLET THEREIN IN COMMUNICATION WITH SAID BORE AND WITH THE EXTERIOR OF SAID BODY, SAID BORE HAVING A FLUID BYPASS CHANNEL ASSOCIATED WITH THE LOWER PORTION THEREOF; A PISTON MOVABLE WITHIN SAID BORE, SAID PISTON INCLUDING CONDUIT MEANS COMMUNICATING WITH THE UPPER PORTION OF SAID BORE AND PASSING THROUGH A SURFACE OF SAID PISTON IMMEDIATELY ADJACENT A WALL OF SAID BORE, SAID PISTON BEING MOVABLE RELATIVE TO SAID BODY PORTION FOR ALTERNATELY BLOCKING THE FLOW OF FLUID THROUGH SAID TUBULAR MEANS, PLACING THE INTERIOR OF SAID TUBULAR MEANS ABOVE THE RESPECTIVE BYPASS VALVE IN COMMUNICATION THROUGH SAID CONDUIT MEANS, AND FLUID OUTLET WITH THE PRODUCING ZONE IN WHICH THE RESPECTIVE VALVE IS LOCATED, AND OPENING THE INTERIOR OF SAID TUBULAR MEANS TO PERMIT FLUID TO FLOW THROUGH SAID CONDUIT MEANS AND BYPASS CHANNEL TO THE NEXT LOWER PRODUCING ZONE; AND RESILIENT BIASING MEANS ASSOCIATED WITH SAID BYPASS VALVE FOR URGING SAID PISTON RELATIVE TO SAID TUBULAR MEANS INTO A POSITION WHEREBY FLOW OF FLUID THROUGH SAID TUBULAR MEANS IS BLOCKED. 